Not Applicable
1. Field of the Invention
This invention relates generally to brake lights, and more particularly to a dual function brake and turn signal light emitting diode lamp.
2. Description of Related Art
The light emitting diode lamp of the present invention is particularly useful for replacing incandescent lamps used in automobiles and other motor vehicles and are applicable to the manufacture of replacement LED lamps for both single filament and dual filament incandescent bulbs. LED""s typically operate at voltages between 1.7 and 2.2 volts.
A typical prior art incandescent lamp generally employs a type S-8 glass bulb cemented in a brass bayonet base having dual contacts. A similar incandescent lamp is described in Devir et al., U.S. Pat. No. 4,603,278. Incandescent vehicle signal-lamp lamps consume a relatively large amount of power, generate a large amount of heat and have a relatively short life.
LED lamps designed to replace vehicle incandescent lamps require bases similar to the standard bayonet base. To be effective an LED lamp must be adapted to produce an intense light when viewed by the human eye and must provide for effective heat dissipation to avoid impairing the LED""s. It also must be designed to operate within the range of voltages present in motor vehicles so as to not over-voltage the LED""s. Finally, some models of motor vehicles ground the brake circuit when the brake is not activated to prevent any accidental activation of the brake lights; accordingly, an effective LED lamp designed to replace a dual filament lamp must contain circuitry enabling the LED""s to be activated with either the tail lamp circuit or the brake light circuit.
Roney et al., U.S. Pat. No. 5,632,551, teaches one approach to solving the problems of cooling the LED""s. Roney teaches an LED lamp as used in truck trailers and/or tractors. The LED""s are mounted on a printed circuit board (PCB). The LED""s are embedded in resin to facilitate the conduction of heat away from the LED""s so that the heat will not cause the LED""s to degrade and lose brightness. This lamp is not designed to fit in standard automotive lamp sockets. A second approach to the cooling problem is given by U.S. Pat. No. 5,575,459 (Anderson) which describes an AC LED lamp that uses air holes to provide air circulation and cooling for an LED lamp. This lamp is not suitable for motor vehicle use. U.S. Pat. No. 6,045,240 (Hochstein) presents a third solution to the problem of cooling the LED""s by teaching the use of a heat sink to cool an LED array.
Cheselske, U.S. Pat. No. 5,160,200, teaches a similar type of LED lamp having a wedge base. It provides a parallel string of LED""s soldered and rolled up for 2-volt dc operation. The roll is placed in a housing with two leads extending out the wedge type base. No provisions are made for 12-volt operation, dual element operation, voltage control, heat dissipation, or brightness enhancement.
Huang, U.S. Pat. No. 5,947,588, describes an LED lamp where an LED array is mounted on a printed circuit board which is in turn mounted on a standard automotive bayonet type base. The LED""s are directly connected to the electrical contacts on the bayonet base. The patent shows an embodiment of the lamp to replace a dual filament lamp. The patent does not describe the circuit connections of the LED""s to the contacts, but either the LED""s are grouped into two setsxe2x80x94one for use as tail lights and a second for use as brake lightsxe2x80x94or the LED""s are connected in parallel so that all LED""s are illuminated when either the tail light or the brake light circuit is energized. If the LED""s are grouped in the two sets then all of the LED""s cannot be energized at once resulting in dimmer tail light and brake lights. On the other hand, if the circuits are connected in parallel so that all LED""s would be energized if either tail lamp or brake lamp circuit were energized, the array would not work as tail lamps in automobiles in which the brake lamp is grounded when the brake is not activated. Also, if this configuration did work in some vehicles, the tail lamps and the brake lamps would be illuminated with equal intensity, that is the brake lights would not be brighter. The patent discusses the problem of low intensity by suggesting the addition of more LED""s; this would make the array larger than a standard incandescent lamp which in turn would result in the LED lamp being unable to fit into many tail lamp assemblies. Also, this configuration of LED lamp will not fit into many recessed automotive sockets and lamp assemblies.
Wesson, U.S. Pat. No. 6,371,636 B1, teaches a light emitting diode lamp for use in vehicle tail, brake or turn signal lamp fixtures for integrated single and dual element operation. The module has integrated dual element control circuitry, voltage and current control circuitry, brightness enhancement circuitry, and LED circuitry built into the universal body to produce a bright, reliable, long life, energy efficient LED lamp that fits all vehicles.
The above-described references are hereby incorporated by reference in full.
The prior art teaches a light emitting diode lamp for use in a vehicle such as an automobile. However, the prior art does not teach a support sleeve for supporting first and second printed circuit boards in the present arrangement. The present invention fulfills these needs and provides further related advantages as described in the following summary.
The present invention teaches certain benefits in construction and use which give rise to the objectives described below.
The present invention provides a light emitting diode lamp for use in a brake light bulb socket of an automobile or similar vehicle. In the preferred embodiment, the light emitting diode lamp can be used as both a brake signal and a turn signal. The light emitting diode lamp includes first and second printed circuit boards having first and second pluralities of light emitting diodes mounted thereupon for emitting monochromatic light in response to power signals supplied from the automobile. The light emitting diode lamp further includes a body adapted to form a bayonet connection, a base having at least one contact, and a support sleeve having a wiring conduit, a support tray, and at least two support stanchions for supporting the first printed circuit board. Finally, the light emitting diode lamp includes an electrical control means electrically connecting the first and second contacts with the first and second printed circuit boards, and a lens cap having a planar front face integrally formed with a cylindrical lens sidewall that terminates in a lens perimeter.
A primary objective of the present invention is to provide a light emitting diode lamp having advantages not taught by the prior art.
Another objective is to provide a light emitting diode lamp that is impact resistant and provides a maximum output of monochromatic light with minimal heat buildup.
A further objective is to provide a light emitting diode lamp having a support sleeve that supports first and second printed circuit boards in an operable relationship for maximum output of monochromatic light while maintaining the high impact resistance.